Computing Essentials

USB Standard Ports
Most desktop and laptop computers come with a standard set of ports for connect-
HDMI ing a monitor, keyboard, and other peripheral devices. The most common ports
follow.
Thunderbolt
• Universal serial bus (USB) ports can be used to connect several devices to the
Ethernet system unit and are widely used to connect keyboards, mice, printers, storage
devices, and a variety of specialty devices. One such device, a USB TV tuner card,
Figure 5-22  Cables allows users to view and record television programs. To learn how you can use a
TV tuner card, see Making IT Work for You: TV Tuners on page 127. A single USB
port can be used to connect many USB devices to the system unit.

• High Definition Multimedia Interface (HDMI) ports provide high-definition video
and audio, making it possible to use a computer as a video jukebox or an HD
video recorder.

• Thunderbolt ports, first introduced in Apple’s MacBook Pro computer, provide
high-speed connections. A single port can connect up to seven separate devices
connected one to another. Thunderbolt ports promise to replace a number of dif-
ferent types of ports including Mini DisplayPorts.

• Ethernet ports are a high-speed networking port that has become a standard for
many of today’s computers. Ethernet allows you to connect multiple computers for
sharing files, or to a DSL or cable modem for high-speed Internet access.

Specialized Ports
In addition to standard ports, there are numerous specialty ports. The most common
include:

• External Serial Advanced Technology Attachment (eSATA) ports provide high-
speed connections for external hard-disk drives, optical discs, and other large sec-
ondary storage devices.

• Musical instrument digital interface (MIDI) ports are a special type of port for
connecting musical instruments like an electronic keyboard to a sound card. The
sound card converts the music into a series of digital instructions. These instruc-
tions can be processed immediately to reproduce the music or saved to a file for
later processing.

• Mini DisplayPort (MiniDP or mDP) ports are audiovisual ports typically used
to connect large monitors. These ports are used with many Apple Macintosh
computers.

• VGA (Video Graphics Adapter) and DVI (Digital Video Interface) ports provide
connections to analog and digital monitors, respectively. DVI has become the most
commonly used standard, but VGA ports are still provided on almost all systems
for compatibility with older/lower-cost monitors.

• FireWire ports provide high-speed connections to specialized FireWire devices
such as camcorders and storage devices.

Cables
Cables are used to connect exterior devices to the system unit via the ports. One end of
the cable is attached to the device, and the other end has a connector that is attached
to a matching connector on the port. (See Figure 5-22.)

126 chapter 5

Making IT work for you

TV TUNERS

Do you already use a DVR (digital video recorder) in order to record your favorite TV shows? Although many
cable and satellite companies offer this device, did you know that Windows Media Center can perform the
same function? All you need is a device called a TV tuner that connects your antenna or cable to your com-
puter. Below are the steps to turn your Windows-based computer into a DVR. (Please note that the following
specifics do not apply to all versions of TV tuners and media players.)

Installing a TV Tuner  A TV tuner is essentially a piece of hardware that allows your computer to process and display a cable
or TV signal. Although some (usually pricey) PCs may include this technology, it is usually necessary to purchase it separately.
The easiest ones to install are those that connect externally to a USB port, such as the Hauppauge Hybrid WinTV-HVR.

• 1 Plug the TV tuner into an available USB port on your computer.
• 2 Connect a coaxial cable directly from your cable outlet or over-the-air

antenna to the back of the TV tuner. If Windows does not automatically
install the tuner, consult the user manual for instructions.

• 3 With your TV tuner installed, it will guide you through a setup process,
including a long scan for all available channels from your cable or
antenna.

Using a Software Media Center  The utility, Kodi, must be downloaded from the Internet. Although it contains many tools to
manage your music, photos, and movies, we will focus on its DVR capabilities for TV and cable. (Please note that there are dif-
ferent versions of Kodi and that some of the specifics presented here may not apply to all versions.)

• 1 Visit http://kodi.tv/download and click the installer for your operating system and download the program.
• 2 Run the installation file and follow the prompts.
• 3 Click on Settings, then Add-ons, then select

Disabled add-ons, and enable the MythTV
PVR Client add-on.

• 4 Click the home button located in the lower
right of the window, then scroll right and click
on TV, and then select Channels.

• 5 To record a program, locate the program and
press record.

• 6 To view your recorded TV shows, return to
the home screen and select the TV sub menu
recordings. Click on the episode you wish to
view.

If you have a high-speed wireless network and several PCs in your home, you will have the capability to watch your
recorded shows via Kodi’s streaming ability.

127

Power Supply

Computers require direct current (DC) to power their electronic components
and to represent data and instructions. DC power can be provided indirectly by
converting alternating current (AC)
tips Does your laptop seem to be losing its charge sooner than it used from standard wall outlets or directly
to? These batteries do lose power over time; however, you can take from batteries.

some steps to slow down the aging process. • Desktop computers have a power
supply unit located within the sys-
1 Balance adapter and battery use. The best practice is to use the laptop on tem unit. (See Figure 5-23.) This unit

battery power for a little while without draining it completely (50 percent
charge, for example), followed by charging it back to 100 percent. Modern
batteries should not be drained to 0 percent each day. plugs into a standard wall outlet,

2 Calibrate it. Your laptop’s manufacturer will recommend that you calibrate, or converts AC to DC, and provides the
power to drive all of the system unit
reset, your battery every few months. Follow its guidelines on the web or in your
instruction manual, as it will ensure that the battery meter in your operating components.
system is accurate and that you are getting the expected charge time.
• Laptops typically use AC adapters
3 Avoid excessive heat. High temperatures can accelerate the deterioration of that are located outside the system
unit. (See Figure 5-24.) AC adapt-
modern batteries. Therefore, avoid exposure to excessive heat and consider ers plug into a standard wall outlet,
purchasing a laptop cooler or fan.

4 Proper storage. If you are not going to use your laptop for a few weeks, most convert AC to DC, provide power to
manufacturers recommend that you remove the battery. drive the system unit components,

and can recharge the batteries. These
computers can be operated either using
an AC adapter plugged into a wall outlet or using bat-
tery power. Their batteries typically provide sufficient
power for up to eight hours before they need to be
recharged.

• Most tablets and mobile devices use internal AC adapt-
ers that use a cable to connect to a standard wall outlet.
Some smartphones, however, use a wireless charging
platform eliminating the cable. (See Figure 5-25.) Unlike
most laptops, most tablets, mobile devices, and wear-
able computers can operate only using battery power.
Their AC adapters or charging platforms are only used
to recharge batteries.

Figure 5-23  Power supply unit

Figure 5-24  AC adapter Figure 5-25  Wireless charging platform
128 chapter 5

concept check

What are ports? What do they do?
Describe four standard ports and five specialized ports.
What is a power supply unit? What is an AC adapter? What is a charging platform?

Electronic Data and Instructions

Have you ever wondered why it is said that we live in a digital world? It’s because
computers cannot recognize information the same way you and I can. People fol-
low instructions and process data using letters, numbers, and special characters. For
example, if we wanted someone to add the numbers 3 and 5 together and record the
answer, we might say “please add 3 and 5.” The system unit, however, is electronic
circuitry and cannot directly process such a request.

Our voices create analog, or continuous, signals that vary to represent different
tones, pitches, and volume. Computers, however, can recognize only digital electronic
signals. Before any processing can occur within the system unit, a conversion must
occur from what we understand to what the system unit can electronically process.

Numeric Representation

What is the most fundamental statement you can make about electricity? It is sim-
ply this: It can be either on or off. Indeed, there are many forms of technology that
can make use of this two-state on/off, yes/no, present/absent arrange-
ment. For instance, a light switch may be on or off, or an electric circuit
open or closed. A specific location on a tape or disk may have a positive
Decimal Binary Hex
00000000 00
charge or a negative charge. This is the reason, then, that a two-state or 00 00000001 01
binary system is used to represent data and instructions. 00000010 02
The decimal system that we are all familiar with has 10 digits (0, 1, 00000011 03
2, 3, 4, 5, 6, 7, 8, 9). The binary system, however, consists of only two 01 00000100 04
digits—0 and 1. Each 0 or 1 is called a bit—short for binary digit. In the 00000101 05
02 00000110 06
00000111 07
system unit, the 1 can be represented by a negative charge and the 0 by 03 00001000 08
no electric charge. In order to represent numbers, letters, and special 00001001 09
characters, bits are combined into groups of eight called bytes. When- 04 00001010 0A
00001011 0B
ever you enter a number into a computer system, that number must be 05 00001100 0C
converted into a binary number before it can be processed. 06

Any number can be expressed as a binary number. Binary numbers,
however, are difficult for humans to work with because they require so
many digits. Instead, binary numbers are often represented in a for- 07
mat more readable by humans. The hexadecimal system, or hex, uses 08

16 digits (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F) to represent binary 09
numbers. Each hex digit represents four binary digits, and two hex dig-
its are commonly used together to represent 1 byte (8 binary digits). 10

(See Figure 5-26.) You may have already seen hex when selecting a color 11
in a website design or drawing application, or when entering the pass-
word for access to a wireless network. 12

Character Encoding 13 00001101 0D

As we’ve seen, computers must represent all numbers with the binary 14 00001110 0E
system internally. What about text? How can a computer provide repre-
sentations of the nonnumeric characters we use to communicate, such 15 00001111 0F
as the sentence you are reading now? The answer is character encoding
schemes or standards. Figure 5-26  Numeric representations

The System Unit 129

Character encoding standards assign a unique sequence of bits to each charac-
ter. Historically, personal computers used the ASCII (American Standard Code for
Information Interchange) to represent characters, while mainframe computers used
EBCDIC (Extended Binary Coded Decimal Interchange Code). These schemes were
quite effective; however, they are limited. ASCII, for example, only uses 7 bits to repre-
sent each character, which means that only 128 total characters could be represented.
This was fine for most characters in the English language but was not large enough
to support other languages such as Chinese and Japanese. These languages have too
many characters to be represented by the 7-bit ASCII code.

The explosion of the Internet and subsequent globalization of computing have led
to a new character encoding called Unicode, which uses 16 bits. The Unicode standard
is the most widely used character encoding standard and is recognized by virtually
every computer system. The first 128 characters are assigned the same sequence of
bits as ASCII to maintain compatibility with older ASCII-formatted information. How-
ever, Unicode uses a variable number of bits to represent each character, which allows
non-English characters and special characters to be represented.

concept check

What is the difference between an analog and a digital signal?
What are decimal and binary systems? How are they different?
Compare EBCDIC, ASCII, and Unicode.

Careers in IT Computer technicians repair and install computer components and
systems. They may work on everything from personal computers and
Now that you know about system units, I’d mainframe servers to printers. Some computer technicians are respon-
sible for setting up and maintaining computer networks. Experienced
“ like to tell you about my career as a computer computer technicians may work with computer engineers to diag-
”technician. nose problems and run routine maintenance on complex systems. Job
growth is expected in this field as computer equipment becomes more
complicated and technology expands.

Employers look for those with certification in computer repair or
associate’s degrees from professional schools. Computer technicians
also can expect to continue their education to keep up with technologi-
cal changes. Good communication skills are important in this field.

Computer technicians can expect to earn an annual salary in
the range of $37,000 to $47,000. Opportunities for advancement typi-
cally come in the form of work on more advanced computer systems.
Some computer technicians move into customer service positions or go
into sales.

130 chapter 5

A LOOK TO THE FUTURE

Chips inside Your Brain processing images. This chip would communicate wirelessly
with a camera located inside special eyeglasses worn by the
Have you ever thought it would be possible to be able to com- individual. The images captured by that camera would be
municate with a computer .  .  . by merely thinking? Simple processed by the chip and then fed directly to the nerves in
computer implants are used on a regular basis to improve this area of the brain. Getting close to the world of the unbe-
hearing or reduce the risk of heart attack. More recently, lievable, researchers are improving on the ability of comput-
implants have been used to regulate drug intake and improve ers to actually read human thoughts. Currently, one research
prosthetics. In the future you may use various devices (usu- team has been able to use a chip implant and computer to
ally worn on the head) that can use your basic thoughts to read the thoughts of a stroke victim in order to allow her to
move objects, such as wheelchairs. However, the future will move a robotic hand. Although the success rate is not 100
lie in implanted microchips that
can communicate directly with percent and the processing is
our nerve cells. Although their limited to basic movements,
initial purpose will be to treat the patient has already been
a variety of medical conditions, able to get the robotic arm to
they could eventually (and con- hold a cup of coffee by think-
troversially) be used to improve ing about it. This research will
various brain functions of hopefully lead to improved,
otherwise healthy individuals. thought-controlled prosthetic
Technology has been making devices for m­illions of dis-
better implants, and will con- abled individuals.
tinue to evolve to improve our
lives as we look to the future. Many ethicists are con-
cerned by the potential use of
For over a decade, doctors such chips to improve human
have been able to use deep abilities instead of treating
brain stimulation (DBS) to treat medical conditions. For exam-
several disorders such as Par- ple, with tiny chips being able
kinson’s disease. As success- to store so much, people could
ful as it has been for many use brain implants to improve
patients, those implants simply their memory. This can lead to
send preset electrical impulses a variety of scenarios where
to the brain. They do not involve an active communication the individual with the implants
between nerve cells and machines. Researchers working on could have an unfair advantage over those who don’t have
a chip known as ReNaChip hope to change this by using a them. However, others disagree, arguing that the integra-
programmable computer chip that is responsive to what is tion of technology and biology is to be expected, and it
going on in the patient’s brain. This silicon chip can measure is nothing more than the next step in human evolution. If
the brain’s electrical activity and then deliver the appropri- such a technology became widespread and affordable,
ate stimulation when and where it is needed. would you opt to receive a chip implant? Would you make a
distinction between using one for a medical condition and
Another brain implant that is currently being developed simply for improving your mental abilities? Do you think the
aims to help the blind regain some sight. A microchip is future of humanity lies in the merging of technology with
implanted in the brain’s visual cortex, which is responsible for human biology?

131

VISUAL SUMMARY The System Unit

SYSTEM UNIT SYSTEM BOARD

System unit (system chassis) contains electronic compo- The system board (mainboard or motherboard) controls
nents. The most common personal computers are desktop, all communication for the computer system. All external
laptop, tablet, smartphones, and wearable computers. and internal devices and components connect to it.

Desktop • Sockets provide connection points for chips (silicon
Desktop system units are located in a separate case; tower
unit (tower computer) has vertical system unit; all-in-one chips, semiconductors, integrated circuits). Chips are
computer combines system unit and monitor. mounted on chip carriers.

Laptop • Slots provide connection points for specialized cards
Laptop system units contain secondary storage devices
and input devices. Specialty laptops include two-in-one or circuit boards.
laptops (touch screen and fold flat), gaming laptops (high-
end graphics and fast processors), ultrabooks, also known • Bus lines provide pathways to support
as ultraportables, and mini notebooks (lighter, thinner,
longer battery life). communication.

Tablet
Tablet system units are located behind the monitor. They
are smaller, lighter, and generally less powerful than lap-
tops and use a virtual keyboard. Mini tablets are a smaller
version of a traditional tablet.

Smartphones
Smartphones are the most popular mobile device; extend cell
phones by providing computing power to capture video, send
audio and video, run apps, connect to the Internet, and more.

Wearable Computers
Wearable computers (wearable devices) contain an
embedded computer on a chip. The most common wear-
able computers are smartwatches and activity trackers.

Components
Each type of system unit has the same basic components
including system board, microprocessor, and memory.

132 chapter 5

To efficiently and effectively use computers, you need to understand the functionality of the basic components in the
system unit: system board, microprocessor, memory, expansion slots and cards, bus lines, ports, and cables. Addition-
ally, you need to understand how data and programs are represented electronically.

MICROPROCESSOR EXPANSION SLOTS AND CARDS

In most personal computers, the central processing unit Most computers allow users to expand their systems by
(CPU) or processor is contained on a single chip called the providing expansion slots on their system boards to
microprocessor. It has two basic components: a control accept expansion cards.
unit and ALU.
Examples of expansion cards include graphics cards,
Microprocessor Chips network interface cards (NIC; network adapter cards),
A word is the number of bits that can be accessed by the and wireless network cards.
microprocessor at one time. Clock speed represents the
number of times the CPU can fetch and process data or SD cards are fingernail-size expansion cards used pri-
instructions in a second. marily for laptop computers, tablets, and smartphones.
They connect to expansion slots within these devices.
Multicore processors can provide multiple indepen-
dent CPUs. Parallel processing requires programs that BUS LINES
allow multiple processors to work together to run large
complex programs. Bus lines, also known as buses, provide data pathways
that connect various system components. Bus width is the
Specialty Processors number of bits that can travel simultaneously.
Specialty processors include graphics coprocessors, also
known as GPU or graphics processing unit (processes System buses connect CPU and memory. Expansion
graphic images), and processors in automobiles (moni- buses connect CPU and slots.
tor fuel efficiency, satellite entertainment, and tracking Expansion Buses
systems). Three principal expansion bus types:

MEMORY • USB (universal serial bus) can connect from one USB

Memory holds data, instructions, and information. There device to another or to a common point (hub) and
are three types of memory chips. then onto the system board.

RAM • FireWire bus is similar to USB bus but more
RAM (random-access memory) chips are called tempo-
rary or volatile storage because their contents are lost if specialized.
power is disrupted.
• Cache memory is a high-speed holding area for fre- • PCI Express (PCIe) bus is widely used; provides a

quently used data and information. single dedicated path for each connected device.

• DIMM (dual in-line memory module) is used to

expand memory.

• Virtual memory divides large programs into parts that

are read into RAM as needed.

ROM
ROM (read-only memory) chips are nonvolatile storage
and control essential system operations.

Flash Memory
Flash memory does not lose its contents when power is
removed.

The System Unit 133

PORTS POWER SUPPLY

Power supply units convert AC to DC and power desk-
tops. AC adapters power laptops and tablets and recharge
batteries. Some smartphones use wireless charging
platforms.

Ports are connecting sockets on the outside of the system ELECTRONIC REPRESENTATION
unit.
Human voices create analog (continuous) signals; com-
Standard Ports puters only recognize digital electronic signals.
Four standard ports are
• USB (universal serial bus)—widely used to connect Numeric Representation
Data and instructions can be represented electronically
keyboards, mice, printers, and storage devices; one with a two-state or binary system of numbers (0 and 1).
port can connect several devices to system unit. Each 0 or 1 is called a bit. A byte consists of 8 bits. Hexa-
decimal system (hex) uses 16 digits to represent binary
• HDMI (high definition multimedia interface)— numbers.

provides high-definition video and audio. Character Encoding
Character encoding standards assign unique sequences of
• Thunderbolt—provides high-speed connections to up bits to each character. Three standards are
• ASCII—American Standard Code for Information
to seven Thunderbolt devices at once, such as external
hard drives and monitors. Interchange. Historically used for personal computers.

• Ethernet—high-speed networking port that has • EBCDIC—Extended Binary Coded Decimal Inter-

become a standard for many of today’s computers. change Code. Historically used for mainframe
computers.
Specialized Ports
Five specialty ports are eSATA (external serial advanced • Unicode—16-bit code, most widely used standard.
technology attachment) for high-speed connections to
large secondary storage devices, MIDI for digital music, CAREERS IN IT
Mini DisplayPort (MiniDP, mDP) for large monitors,
VGA (Video Graphics Adapter) and DVI (Digital Video Computer technicians repair and install computer compo-
Interface) for connecting to monitors, and Firewire for nents and systems. Certification in computer repair or an
high-speed connection to devices such as camcorders and associate’s degree from professional schools is required.
secondary storage. Salary range is $37,000 to $47,000.

Cables
Cables are used to connect external devices to the system
unit via ports.

134 chapter 5

KEY TERMS

AC adapter (128) memory (122)
activity tracker (118) microprocessor (120)
all-in-one (116) Mini DisplayPort (MiniDP, mDP) port (126)
analog (129) mini notebook (117)
arithmetic-logic unit (ALU) (120) mini tablets (117)
arithmetic operation (120) motherboard (119)
ASCII (130) multicore processor (121)
binary system (129) musical instrument digital interface
BIOS (basic input/output system) (123)
bit (129) (MIDI) port (126)
bus (124) network adapter card (123)
bus line (124) network interface card (NIC) (123)
bus width (124) parallel processing (121)
byte (129) PCI Express (PCIe) (125)
cable (126) personal computer (116)
cache memory (122) port (125)
central processing unit (CPU) (120) power supply unit (128)
character encoding standards (130) processor (120)
chip (119) random-access memory (RAM) (122)
chip carriers (119) read-only memory (ROM) (122)
clock speed (121) SD card (124)
computer technician (130) semiconductor (119)
control unit (120) silicon chip (119)
coprocessor (121) slot (119)
desktop (116) smartphone (118)
digital (129) smartwatch (118)
DIMM (dual in-line memory module) (122) socket (119)
DVI (Digital Video Interface) port (126) system board (119)
EBCDIC (130) system bus (124)
Ethernet port (126) system chassis (116)
expansion bus (124) system unit (116)
expansion card (123) tablet (117)
expansion slot (123) tablet computer (117)
external Serial Advanced Technology Thunderbolt port (126)
tower computer (116)
Attachment (eSATA) port (126) tower unit (116)
FireWire bus (125) two-in-one laptops (117)
FireWire port (126) ultrabooks (117)
flash memory (122) ultraportables (117)
gaming laptops (117) Unicode (130)
GPU (graphics processing unit) (121) universal serial bus (USB) (125)
graphics card (123) universal serial bus (USB) port (126)
graphics coprocessor (121) VGA (Video Graphics Adapter)
hexadecimal system (hex) (129)
High Definition Multimedia Interface port (126)
virtual memory (122)
(HDMI) port (126) wearable computer (118)
integrated circuit (119) wearable device (118)
laptop (116) wireless charging platform (128)
logical operation (120) wireless network card (124)
mainboard (119) word (121)

chapter 5 135

MULTIPLE CHOICE

Circle the correct answer.

1. This container houses most of the electrical components for a computer system.

a. chip carrier c. system unit
b. system board d. Unicode

2. The most popular mobile device.

a. all-in-one c. smartphone
b. desktop d. ultrabook

3. The mainboard or motherboard is also known as the:

a. computer c. mobile system
b. board processor d. system board

4. How many bytes can a 32-bit-word computer access at one time?

a. 1 c. 8
b. 4 d. 16

5. In a personal computer system, the central processing unit is typically contained on a
single:

a. bus c. module
b. chip d. RAM

6. This type of memory divides large programs into parts and stores the parts on a second-
ary storage device.

a. direct c. random-access
b. expanded d. virtual

7. Also known as NIC, this adapter card is used to connect a computer to a(n):

a. AIA c. graphics
b. expansion d. network

8. This provides a pathway to connect parts of the CPU to each other.

a. bus c. wired
b. cable d. wireless

9. The specialized port that connects musical instruments like an electronic keyboard to a
sound card.

a. eSATA c. MIDI
b. HDMI d. Thunderbolt

10. Computers can only recognize this type of electronic signal.

a. analog c. digital
b. bus d. maximum

136 chapter 5

MATCHING

Match each numbered item with the most closely related lettered item. Write your answers in
the spaces provided.

a. cache 1. A type of multiprocessor chip that provides two or
b. flash more separate and independent CPUs.
c. multicore
d. NIC 2. A type of memory that is volatile or loses its con-
e. port tents when power is turned off.
f. random-access
g. slots 3. System board component that provides a connec-
h. sockets tion point for specialized cards or circuit boards.
i. system
j. USB 4. Provide connection points for chips.
5. A type of memory that improves processing by

acting as a temporary high-speed holding area
between the memory and the CPU.
6. A type of memory that provides a combination of
features of RAM and ROM.
7. Another name for a network adapter card.
8. This bus connects the CPU to memory on the sys-
tem board.
9. This port can be used to connect many USB devices
to the system.
10. A socket for external devices to connect to the sys-
tem unit.

OPEN-ENDED

On a separate sheet of paper, respond to each question or statement.

1. Describe the five most common types of personal computers.
2. Describe system boards including sockets, chips, chip carriers, slots, and bus lines.
3. Discuss microprocessor components, chips, and specialty processors.
4. Define computer memory including RAM, ROM, and flash memory.
5. Define expansion slots, cards, including graphics cards, network interface cards, wire-

less network cards, and SD cards.
6. Describe bus lines, bus width, system bus, and expansion bus.
7. Define ports including standard and specialized ports. Give examples of each.
8. Describe power supply including power supply units and AC adapters.
9. Discuss electronic data and instructions.

chapter 5 137

DISCUSSION

Respond to each of the following questions.

1 Making IT Work for You: TV TUNERS

Did you know that you can record your favorite TV shows with a computer? Review the Making IT Work
for You: TV Tuners on page 127, and then respond to the following: (a) Do you currently have a DVR in
your home? If so, who is the manufacturer? If not, have you considered purchasing one? Why or why not?
(b) How do the Kodi Media Center DVR capabilities compare with the DVR offered by your cable or satel-
lite company? Use a search engine to help you find these differences. (c) Find at least two USB-based
TV tuners using any online store. Note their prices and specifications. What are their main differences?

2 Privacy: CRYPTOPROCESSORS

Did you know that some systems have specialty processors that automatically encrypt data before stor-
ing? Review the Privacy box on page 121, and respond to the following: (a) Who do you think would need a
cryptoprocessor? Be specific. (b) Do think these processors would be worthwhile for you to protect your
privacy? Why or why not? (c) Are there any reasons why you might not want all your data encrypted?
Explain. (d) Do you think that all computer systems should be required to have cryptoprocessors? Defend
your position.

3 Ethics: JOB LOSS AND WORKING CONDITIONS

Many computer-related products are produced in China, where working conditions are reported to be
well below acceptable standards. Review the Ethics box on page 116, and then respond to the following:
(a) What do you think about products produced in other countries like China? What are the advantages
and disadvantages to consumers? Be specific. (b) What are the ethical issues? Be specific, and defend
your list of issues. (c) Would you be willing to pay more for a computer produced entirely in the United
States? More specifically, would you be willing to pay three times as much for a smartphone? Why or
why not? (d) Do you think consumers have an ethical responsibility to know how goods are produced?
More specifically, would your purchase decisions be affected by knowledge about the working condi-
tions of those who make the product? Why or why not?

4 Environment: RECYCLING COMPUTER HARDWARE

Have you ever wondered what you should do with your old computers, monitors, and mobile devices?
Review the Environment box on page 120, and then respond to the following: (a) What do you typically
do with your used or broken computers and mobile devices? (b) What are three alternatives to throwing
these devices in the trash? (c) Using a search engine, find one nonprofit organization near you that will
accept used computers. List the name and URL. (d) Visit the waste management or recycling page of your
local government’s website. If it does not have a website, contact it. What is its recommended procedure
for discarding your computers and other electronic devices?

138 chapter 5

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CHAPTER 5

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Alamy; 5-3, 5-4, page 132 (top-left): Courtesy of Dell Inc.; 5-5: © epa european pressphoto agency b.v./Alamy; 5-6:
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chapter 5 139

6chapter Input and Output

140

Why should I read this chapter?

Input and output devices have seen staggering advances in recent
years. A typical cell phone now has dozens of input sensors and
display options. In the future, input devices such as tiny attach-
ments to clothes or eyewear will be as common as cell phones.
Augmented reality displays or wearable glasses will integrate
what you see with extensive databases of relevant information.

This chapter covers the things you need to know to be pre-
pared for this ever-changing digital world, including:
• Keyboard design—discover how wireless and virtual key-

boards improve the speed and ease of typing.
• Intuitive input devices—learn about advances in touch

screens and voice recognition systems.
• Display technology—discover how webcams and digital

whiteboards can create videos and share presentations.
• Evolving output devices—learn about advances in UHDTVs,

3D printers, and e-books.

Learning Objectives

After you have read this chapter, you should be able to:

1 Define input.
2 Describe keyboard entry including types and features of keyboards.
3 Identify different pointing devices including game controllers and styluses.
4 Describe scanning devices including optical scanners, RFID readers, and recognition devices.
5 Recognize image capturing and audio-input devices.
6 Define output.
7 Identify different monitor features and types including flat panels and e-books.
8 Define printing features and types including inkjet and cloud printers.
9 Recognize different audio and video devices including portable media devices.
10 Define combination input and output devices including multifunctional devices, telephones,

drones, robots, and VR headgear and gloves.
11 Explain ergonomics and ways to minimize physical damage.

141

Introduction How do you send instructions and information to the CPU? How do you
get information out? Here we describe one of the most important places
“Hi, I’m Marie, and I’m a technical writer. I’d where computers interface with people. We input text, music, and even
like to talk with you about input and output speech, but we probably never think about the relationship between what
devices . . . all those devices that help us to we enter and what the computer processes. Input devices translate num-
communicate with a computer. I’d also like bers, letters, special characters, and gestures that people understand into
”to talk about emerging technologies such as a form that computers can process.
virtual reality.
Have you ever wondered how information processed by the system
unit is converted into a form that you can use? That is the role of output
devices. While input devices convert what we understand into what the
system unit can process, output devices convert what the system unit has
processed into a form that we can understand. Output devices translate
machine language into letters, numbers, sounds, and images that people
can understand.

To efficiently and effectively use computers, you need to know about the
most commonly used input devices, including touch screens, game control-
lers, scanners, digital cameras, voice recognition, and audio-input devices.
Additionally, you need to know about the most commonly used output
devices, including monitors, printers, and audio and video output devices.
You also need to be aware of combination input and output devices such as
multifunctional devices and telephones.

What Is Input?

Input is any data or instructions that are used by a computer. They can come
directly from you or from other sources. You provide input whenever you use sys-
tem or application programs. For example, when using a word processing pro-
gram, you enter data in the form of numbers and letters and issue commands such
as to save and to print documents. You also can enter data and issue commands by
pointing to items or using your voice. Other sources of input include scanned or
photographed images.

Input devices are hardware used to translate words, numbers, sounds, images, and
gestures that people understand into a form that the system unit can process. For
example, when using a word processor, you typically use a keyboard to enter text
and a mouse to issue commands. In addition to keyboards and mice, there are a wide
variety of other input devices. These include pointing, scanning, image capturing, and
audio-input devices.

Keyboard Entry

One of the most common ways to input data is by a keyboard. As mentioned in
Chapter 5, keyboards convert numbers, letters, and special characters that people
understand into electrical signals. These signals are sent to, and processed by, the
system unit. Most keyboards use an arrangement of keys given the name QWERTY.
This name reflects the keyboard layout by taking the letters of the first six alphabetic
characters found on the top row of keys displaying letters.

142 chapter 6

Function keys are shortcuts for specific Numeric keypad enters numbers and arithmetic
tasks; F1, for example, typically displays Help. symbols and controls cursor or insertion point.

Windows key displays Navigation keys control the cursor
the Start menu. or insertion point on the screen.

Figure 6-1  Traditional keyboard

Keyboards Laptop keyboard
Virtual keyboard
There are a wide variety of keyboard designs. They range from the full-sized to minia-
ture and can even be virtual. There are four basic categories of keyboards: traditional,
laptop, virtual, and thumb.

• Traditional keyboards—these full-size keyboards are widely used on desktops
and larger computers. The standard U.S. traditional keyboard has 101 keys. Some
traditional keyboards include a few additional special keys. For example, the Win-
dows keyboard includes a Windows key to directly access the Start menu. Tradi-
tional keyboards provide function keys, navigation keys, and a numeric keypad.
Some keys, such as the Caps Lock key, are toggle keys. These keys turn a feature
on or off. Others, such as the Ctrl key, are combination keys, which perform an
action when held down in combination with another key. (See Figure 6-1.)

• Laptop keyboards—these keyboards are smaller than traditional keyboards and are
widely used on laptop computers. While the precise location and number of keys
may differ among manufactures, laptop keyboards typically have fewer keys, do
not include a numeric keypad, and do not have a standard location for the func-
tion and navigation keys. (See Figure 6-2, top.)

• Virtual keyboards—these keyboards are used primarily with mobile devices and
tablets. Unlike other keyboards, virtual keyboards do not have a physical key-
board. Rather, the keys are typically displayed on a screen and selected by touch-
ing their image on the screen. (See Figure 6-2, middle.)

• Thumb keyboards—these keyboards are used on smartphones and other small
mobile devices. Designed primarily for communicating via texting and connecting
to the web, these keyboards are very small. (See Figure 6-2, bottom.)

concept check Thumb keyboard
Figure 6-2  Keyboards
What is input? What are input devices?
List and compare the four categories of keyboards.
What are toggle keys? What are combination keys?

Input and Output 143

Pointing Devices

Figure 6-3  Optical mouse Pointing is one of the most natural of all human gestures. Pointing devices provide an
Figure 6-4  Touch pad intuitive interface with the system unit by accepting physical movements or gestures
Figure 6-5  Multitouch screen such as a finger pointing or moving across a screen and converting these movements
into machine-readable input. There are a wide variety of pointing devices, including
the mouse, touch screen, game controller, and stylus.

Mouse
A mouse controls a pointer that is displayed on the monitor. The mouse pointer usu-
ally appears in the shape of an arrow. It frequently changes shape, however, depend-

ing on the application. A mouse can have one, two, or more
buttons, which are used to select command options and to con-
trol the mouse pointer on the monitor. Some mice have a wheel
button that can be rotated to scroll through information that is
displayed on the monitor.

Although there are several different designs, the optical mouse
is the most widely used. (See Figure 6-3.) It emits and senses light
to detect mouse movement. Traditionally, the detected movements
are communicated to the system unit through a cord. Alternatively,
the cordless or wireless mouse uses radio waves or infrared light
waves to communicate with the system unit. These devices elimi-
nate the mouse cord and free up desk space.

Like a mouse, a touch pad is used to control the mouse pointer
and to make selections. Unlike a mouse, however, a touch pad
operates by moving or tapping your finger on the surface of a
pad. These devices are widely used instead of a mouse with lap-
tops and some types of mobile devices. (See Figure 6-4.)

Touch Screen
A touch screen allows users to select actions or commands by
touching the screen with a finger or penlike device. Multitouch
screens can be touched with more than one finger, which allows
for interactions such as rotating graphical objects on the screen
with your hand or zooming in and out by pinching and stretch-
ing your fingers. Multitouch screens are commonly used with
tablets and smartphones, as well as some laptop computers and
desktop monitors. (See Figure 6-5.)

Game Controllers
Game controllers are devices that provide input to computer
games. While keyboards and traditional mice can be used as game controllers, the four
most popular and specialized game controllers are joysticks, gaming mice, gamepads,
and motion-sensing devices. (See Figure 6-6.)

• Joysticks control game actions by users varying the pressure, speed, and direction
of a control stick.

• Gaming mice are similar to traditional mice with higher precision, faster respon-
siveness, programmable buttons, and better ergonomics.

• Gamepads are designed to be held by two hands and provide a wide array of
inputs including motion, turning, stopping, and firing.

• Motion-sensing devices control games by user movements. For example, Micro-
soft’s Kinect motion-sensing device accepts user movements and spoken com-
mands to control games on the Xbox 360.

144 chapter 6

Gaming mouse Gamepad

Joystick

Motion-sensing device
Figure 6-6  Game controllers

Stylus
A stylus is a penlike device typically used with tablets and
mobile devices. (See Figure 6-7.) A stylus uses pressure to
draw images on a screen. Often, a stylus interacts with
the computer through handwriting recognition software.
Handwriting recognition software translates handwritten
notes into a form that the system unit can process.

concept check Figure 6-7  Stylus

What is a pointing device? Describe four pointing
devices.
What is an optical mouse? What is a multitouch screen?
Describe four game controllers. What is a stylus?

Scanning Devices Input and Output 145

Scanning devices convert scanned text and images into a form that the system unit
can process. There are five types of scanning devices: optical scanners, card readers,
bar code readers, RFID readers, and character and mark recognition devices.
Optical Scanners
An optical scanner, also known simply as a scanner, accepts documents consisting of
text and/or images and converts them to machine-readable form. These devices do not
recognize individual letters or images. Rather, they recognize light, dark, and colored
areas that make up individual letters or images. Typically, scanned documents are
saved in files that can be further processed, displayed, printed, or stored for later use.

Figure 6-8  Document scanner Figure 6-9  3D scanner

There are four basic types of optical scanners: flatbed, document, portable, and 3D.

• Flatbed scanner is much like a copy machine. The image to be scanned is placed
on a glass surface, and the scanner records the image.

• Document scanner is similar to a flatbed scanner except that it can quickly scan
multipage documents. It automatically feeds one page of a document at a time
through a scanning surface. (See Figure 6-8.)

• Portable scanner is typically a handheld device that slides across the image,
m­ aking direct contact.

• 3D scanners use lasers, cameras, or robotic arms to record the shape of an object.
Like 2D scanners, most 3D scanners cannot recognize light, dark, and colored
areas. (See Figure 6-9.)
Optical scanners are powerful tools for a wide variety of end users, including graph-

ics and advertising professionals who scan images and combine them with text.

Card Readers

Nearly everyone uses a credit card, debit card, access (parking or building) card, and/or
some type of identification card. These cards typically have the user’s name, some
type of identification number, and signature on the card. Additionally, encoded infor-
mation is often stored on the card. Card readers interpret this encoded information.

Although there are several different types, by far the most common is the ­magnetic
card reader. The encoded information is stored on a thin magnetic strip located on the
back of the card. When the card is swiped through the magnetic card reader, the infor-
mation is read. Many credit cards, known as smart cards, include additional security
in the form of a microchip embedded in the credit card. This chip contains encrypted
data that makes it nearly impossible for criminals to forge a duplicate card. Some chips
require that you insert the card into a specialized reader, while others only require that
you hold the card near the reader.

Bar Code Readers
You are probably familiar with bar code readers or scanners from grocery stores. These
devices are either handheld wand readers or platform scanners. They contain photo-
electric cells that scan or read bar codes, or the vertical zebra-striped marks printed on
product containers.

There are a variety of different codes including UPC and MaxiCode codes.
• UPCs (Universal Product Codes) are widely used by retail stores to automate

the processes to check out customers, to change product prices, and to maintain
inventory records.
• MaxiCode is widely used by the United Parcel Service (UPS) and others to auto-
mate the process of routing packages, tracking in-transit packages, and locating
lost packages.

146 chapter 6

Smartphones with the appropriate app can also scan codes. (See Figure 6-10  Smartphone bar code reader
Figure 6-10.) For example, after scanning the bar code from a product Figure 6-11  RFID reader
you are thinking of buying, the app Price Check by Amazon will provide
in-store and online price comparisons as well as provide other customer
product reviews.

RFID Readers
RFID (radio-frequency identification) tags are tiny chips that can be
embedded in most everything. They can be found in consumer prod-
ucts, driver’s licenses, passports, and any number of other items. (See
Figure 6-11.) These chips contain electronically stored information that
can be read using an RFID reader located several yards away. They are
widely used to track and locate lost pets; to monitor production and
update inventory; and to record prices, product descriptions, and loca-
tions of retail items.

Character and Mark Recognition Devices
Character and mark recognition devices are scanners that are able to
recognize special characters and marks. They are specialty devices that
are essential tools for certain applications. Three types are
• Magnetic-ink character recognition (MICR)—used by banks to auto-

matically read those unusual numbers on the bottom of checks and
deposit slips. A special-purpose machine known as a reader/sorter
reads these numbers and provides input that allows banks to effi-
ciently maintain customer account balances.
• Optical-character recognition (OCR)—uses special preprinted
characters that can be read by a light source and changed into
machine-readable code. A common OCR device is the handheld
wand reader. (See Figure 6-12.) These are used in department
stores to read retail price tags by reflecting light on the printed
characters.
• Optical-mark recognition (OMR)—senses the presence or absence of
a mark, such as a pencil mark. OMR is often used to score standard-
ized multiple-choice tests.

concept check

What is a scanner? Describe five types of scanning devices.
What is UPC? MaxiCode? Smart cards?
Describe three common character and mark recognition devices.

Image Capturing Devices Figure 6-12  Wand reader

Optical scanners, like traditional copy machines, can make a copy
from an original. For example, an optical scanner can make a digital
copy of a photograph. Image capturing devices, on the other hand, create
or capture original images. These devices include digital cameras
and webcams.

Input and Output 147

Figure 6-13  Digital camera Figure 6-14  Attached webcam

ethics Digital Cameras
Digital cameras capture images digitally and store the images on a memory card or in
You may have heard of the camera’s memory. Most digital cameras are also able to record video as well. (See
instances where webcams were Figure 6-13.) Almost all tablets and smartphones have built-in digital cameras capable
used to broadcast the activities of taking images and video. You can take a picture, view it immediately, and even
of individuals who did not know place it on your own web page, within minutes.
they were being recorded. For Webcams
example, in a famous court Webcams are specialized digital video cameras that capture images and send them to
case, a university student was a computer for broadcast over the Internet. Webcams are built into most smartphones
prosecuted for using a webcam and tablets. Desktop and laptop webcams are either built in or attached to the com-
on an open laptop to secretly puter’s monitor. (See Figure 6-14.)
record his roommate’s intimate
activities. In other situations, Audio-Input Devices
public webcams have recorded
embarrassing footage of Audio-input devices convert sounds into a form that can be processed by the system
people who were not aware unit. By far the most widely used audio-input device is the microphone. Audio input
of the camera. It has been can take many forms, including the human voice and music.
argued that capturing and then Voice Recognition Systems
broadcasting a person’s image
without his or her knowledge
and consent is unethical. What
do you think?

Voice recognition systems use a microphone, a sound card, and special software.
These systems allow users to operate computers and other
tips Have you ever had trouble communi­ devices as well as to create documents using voice commands.
cating with someone who does not As discussed in Chapter 4, most smartphones include a digital
speak ­English? If so, Google Translate may be just assistant that uses voice recognition to accept voice commands
what you need.
to control operations. Apple phones come with Siri, Windows
phones come with Cortana, and Google phones come with
1 Go to translate.google.com. Google Now. These voice recognition systems can perform any
number of operations including scheduling events on your cal-
2 Using the buttons at the top, select the language you endar, composing simple text messages, and looking up facts

will be speaking, followed by the language you want
your words translated to.

3 Click the microphone icon in the box on the left, and on the web. Specialized portable voice recorders are widely
used by doctors, lawyers, and others to record dictation. These
begin speaking clearly into your microphone. In a few
seconds, you will see the translated text in the box on devices are able to record for several hours before connecting
the right. to a computer running voice recognition software to edit, store,

4 Click the speaker icon in the box on the right to hear and print the dictated information. Some systems are even able
to translate dictation from one language to another, such as
the translation.

from English to Japanese.

148 chapter 6

concept check

How are image capturing devices different from an optical scanner?
Describe two image capturing devices.
What are voice recognition systems? Siri? Cortana? Google Now?

What Is Output?

Output is processed data or information. Output typically takes the form of text,
graphics, photos, audio, and/or video. For example, when you create a presentation
using a presentation graphics program, you typically input text and graphics. You also
could include photographs, voice narration, and even video. The output would be the
completed presentation.

Output devices are any hardware used to provide or to create output. They trans-
late information that has been processed by the system unit into a form that humans
can understand. There are a wide range of output devices. The most widely used are
monitors, printers, and audio-output devices.

Monitors

The most frequently used output device is the monitor. Also known as display
screens, monitors present visual images of text and graphics. The output is
often referred to as soft copy. Monitors vary in size, shape, and cost. Almost all,
however, have some basic distinguishing features.

Features

The most important characteristic of a monitor is its clarity. Clarity refers Pixel
to the quality and sharpness of the displayed images. It is a function of
several monitor features, including resolution, dot pitch, contrast ratio,
size, and aspect ratio.

• Resolution is one of the most important features. Images are formed
on a monitor by a series of dots or pixels (picture elements). (See
Figure 6-15.) Resolution is expressed as a matrix of these dots
or pixels. For example, many monitors today have a resolution of
1,920 pixel columns by 1,080 pixel rows for a total of 2,073,600 pixels.
The higher a monitor’s resolution (the more pixels), the clearer the image
produced. See Figure 6-16 for the most common monitor resolutions. Figure 6-15  Monitor resolution

• Dot (pixel) pitch is the distance between each pixel. Most newer monitors have Standard Pixels
a dot pitch of 0.30 mm (30/100th of a millimeter) or less. The lower the dot pitch HD 720 1,280 × 720
(the shorter the distance between pixels), the clearer the images produced. HD 1080 1,920 × 1,080
WQXGA 2,560 × 1,600
• Contrast ratios indicate a monitor’s ability to display images. It compares the light UHD 4K 3,840 × 2,160
intensity of the brightest white to the darkest black. The higher the ratio, the better UHD 5K 5,120 × 2,880
the monitor. Good monitors typically have contrast ratios between 500:1 and 2000:1.

• Size, or active display area, is measured by the diagonal length of a monitor’s view-
ing area. Common sizes are 15, 17, 19, 21, and 24 inches.

• Aspect ratio indicates the proportional relationship between a display’s width and
height. Typically, this relationship is expressed by two numbers separated by a
colon (:). Many older, more square-shaped monitors have a 4:3 aspect ratio. Almost all
newer monitors have a 16:9 aspect ratio designed to display wide-screen content. Figure 6-16  Resolution
standards

Input and Output 149

Another important monitor feature is the ability to accept touch or gesture input
such as finger movements including swiping, sliding, and pinching. While most older
monitors do not support touch input, it is becoming a standard feature of newer
monitors.

Flat-Panel Monitors
Flat-panel monitors are the most widely used type of monitor today. Compared to
other types, they are thinner, are more portable, and require less power to operate.
(See Figure 6-17.)

Almost all flat-panel displays are backlit, meaning that a common source of light
is dispersed over all the pixels on the screen. There are three basic types of flat-panel
monitors: LCD, LED, and OLED.

• LCD (liquid crystal display) is widely used for older monitors and is typically less
expensive.

• LED (light-emitting diode) monitors use similar technology with a more advanced
backlighting technology. They produce better-quality images, are slimmer, and
are more environmentally friendly as they require less power and use fewer toxic
chemicals to manufacture. Most new monitors are LED.

• OLED (organic light-emitting diode) monitors replace the LED monitor’s back-
lighting technology with a thin layer of organic compound that produces light. By
eliminating the backlight, OLED monitors can be even thinner with better power
efficiency and contrast ratios.

Figure 6-17  Flat-panel monitor Curved Monitors
Figure 6-18  Curved monitor
One of the most recent developments is the curved monitor. It uses similar technol-
ogy as flat-panel monitors except it has a concave screen that provides better viewing
angles near the edges of the screen. Curved monitors are widely use for high-end
televisions and for gamers searching for a highly immersive viewing experience. (See
Figure 6-18.) Curved monitors are just beginning to appear in smartphones and wear-
able computers. For smartphones, curved monitors allow the screen to wrap around
the edge of the phone for alternative display and button options. For smartwatches, a
curved screen allows for large displays that contour to the shape of your wrist.

E-book Readers

E-books (electronic books) are traditional printed books in electronic format. These
books are available from numerous sources including many public and private librar-
ies, bookstore websites, and the cloud.
E-book readers (e-readers) are dedi-
cated mobile devices for storing and
displaying e-books and other electronic
media including electronic newspapers
and magazines.
E-book readers have displays that
are typically 6 inches and use a tech-
nology known as e-ink. E-ink pro-
duces images that reflect light like
ordinary paper, making the display
easy to read. Two well-known e-book
readers are Amazon’s Kindle and
Barnes & Noble’s Nook Simple Touch.
(See Figure 6-19.)
Tablets can also display e-books. They
are larger, heavier, and more expensive
than e-book readers. They are also much
Figure 6-19  E-book reader more flexible, with displaying e-books

150 chapter 6

Figure 6-20  Digital whiteboard Figure 6-21  3D UHDTV

being only one of their any number of applications. Unlike dedicated e-book readers, these Figure 6-22  Digital projector
tablets use LCD displays that provide crisp, colorful images; however, they are difficult to
read in bright light due to their reflective nature. Two well-known traditional tablets are
Apple’s iPad and Samsung’s Galaxy Tab.

To learn more about e-books, see Making IT Work for You: E-books, on page 152.

Other Monitors
There are several other types of monitors. Some are used for more specialized applica-
tions, such as making presentations and watching television.

• Digital or interactive whiteboards are specialized devices with a large display con-
nected to a computer or projector. The computer’s desktop is displayed on the dig-
ital whiteboard and controlled using a special pen, a finger, or some other device.
Digital whiteboards are widely used in classrooms and corporate boardrooms.
(See Figure 6-20.)

• Ultra-high-definition television (UHDTV) delivers a much clearer and more
detailed wide-screen picture than regular HDTV. Because the output is digital,
users can readily freeze video sequences to create high-quality still images. The
video and still images can then be edited and stored for later use. This technology
is very useful to graphic artists, designers, and publishers. One of the most recent
and dramatic advances is 3D UHDTV. (See Figure 6-21.) Using special viewing
glasses, 3D UHDTV provides theater-quality three-dimensional viewing.

• Digital projectors project the images from a traditional monitor onto a screen or
wall. This is ideal for presentations or meetings when several people need to see
the screen at the same time. Further, projectors tend to be more portable and less
expensive than a similarly sized monitor. Unfortunately, projected images can be
difficult to see in bright rooms, so they are best used in dark rooms with curtains
or no windows. (See Figure 6-22.)

concept check

Define these monitor features: clarity, resolution, dot pitch, contrast ratios, size,
and aspect ratio.
Describe flat-panel, curved, LCD, LED, and OLED monitors.
What are e-book readers, digital whiteboards, UHDTVs, and digital projectors?

Input and Output 151

Making IT work for you

E-BOOKS

Are you tired of carrying a book bag filled with textbooks? Have you ever wished you could have a reference
book or text at your fingertips, instead of at home on a bookshelf? E-books are the solutions to these prob-
lems, and this guide will discuss their benefits, as well as various options on how to access and read them.

Benefits of E-books  Because e-books are digital, they offer a wide range of benefits:

• 1 Transporting. Books can take up a large volume of space in any
home (or your school bag). With e-books, you can store over a
thousand books in one small device!

• 2 Searching. Type any keyword, and you will be taken to the
page(s) where that word appears. This is much faster than
using an index.

• 3 Bookmarking. Mark any number of pages as important. This is
an improvement over having countless physical bookmarks or
folded pages.

• 4 Adding highlights and notes. All marks on an e-book are digital. They can be added and removed easily. The
same could not be said for physical textbooks.

• 5 Purchasing. Buying an e-book can take less than a minute, as it is downloaded instantly to your device.
Prices also tend to be lower than those for physical books.

Reading E-books  Once you decide to purchase an e-book, you may be surprised by the number of devices you can use to read it.

• 1 E-book reader. Dedicated e-book readers, such as
the Amazon Kindle and the Barnes & Noble
Nook, can be purchased for less than
$100. If it is important for you to read
in direct sunlight or areas with heavy
lighting, the e-ink used by these devices
will be desirable.

• 2 Smartphones and tablets. Do you already
own a smartphone or tablet that you take everywhere?
If so, you may want to download the free apps from e-book
sellers to avoid the cost of a separate e-book reader.
The reading experience on these apps is excellent with the touch-screen interface present in these
devices.

• 3 Laptop and desktop computers. Although many e-book retailers make apps for your computer, sellers such as
Google allow you to read books purchased from its Google Play store with nothing more than a web browser.
Most e-book sellers offer the synchronization of your e-books and notes with their cloud services. This allows you to start
reading a book using your tablet, for example, and pick up where you left off with your smartphone.

152

Printers environment

Even as many individuals, schools, and businesses are trying to go paperless, printers Have you considered the
remain one of the most used output devices. You probably use a printer to print home- environmental impact of using
work assignments, photographs, and web pages. Printers translate information that your inkjet printer? Whenever
has been processed by the system unit and present the information on paper. Printer possible, don’t print. Use e-mail
output is often called hard copy. attachments, and encourage
your school to use web
Features technologies that let students
There are many different types of printers. Almost all, however, have some basic upload their schoolwork. If you
distinguishing features, including resolution, color capability, speed, memory, and must print, buy ink cartridges
duplex printing. that are made with mostly
recycled plastic. And when your
• Resolution for a printer is similar to monitor resolution. It is a measure of the ink runs out, bring the cartridge
clarity of images produced. Printer resolution, however, is measured in dpi to a retailer that will make sure
(dots per inch). (See Figure 6-23.) Most printers designed for personal use aver- it is recycled. Many retailers
age 1,200 by 4,800 dpi. The higher the dpi, the better the quality of images often offer a discount on a new
produced. cartridge when you turn in an
empty one.
• Color capability is provided by most printers today. Users typically have the option
to print either with just black ink or with color. Because it is more expensive to
print in color, most users select black ink for letters, drafts, and homework. The
most common black ink selection is grayscale, in which images are displayed
using many shades of gray. Color is used more selectively for final reports contain-
ing graphics and for photographs.

• Speed is measured in the number of pages printed per minute. Typically, printers
for personal use average 15 to 19 pages per minute for single-color (black) output
and 13 to 15 pages per minute for color output.

• Memory within a printer is used to store printing instructions and documents
waiting to be printed. The more memory, the faster it will be able to print large
documents.

• Duplex printing allows automatic printing on both sides of a sheet of paper.
Although not currently a standard feature for all printers, it will likely become
standard in the future as a way to reduce paper waste and to protect the
environment.

Inkjet Printers
Inkjet printers spray ink at high speed onto the surface of paper. This process pro-
duces high-quality images in a variety of colors, making it ideal for printing photos.

300 by 1,200 by
1,200 dpi 4,800 dpi

Figure 6-23  DPI comparison Input and Output 153

Figure 6-24  Inkjet printer (See Figure 6-24.) Inkjet printers are relatively inexpensive and are the
Figure 6-25  3D printer most widely used printers. In addition, they are reliable and quiet. The
most costly aspect of inkjet printers is replacing the ink cartridges. For this
reason, most users specify black ink for the majority of print jobs and use
the more expensive color printing for select applications. Typical inkjet
printers produce 15 to 19 pages per minute of black-only output and 13 to
15 pages of color output.

Laser Printers
The laser printer uses a technology similar to that used in a photocopying
machine. Laser printers use a laser light beam to produce images with
excellent letter and graphics quality. More expensive than inkjet printers, laser print-
ers are faster and are used in applications requiring high-quality output.
There are two categories of laser printers. Personal laser printers are less expensive
and are used by a single user. They typically can print 15 to 17 pages a minute. Shared
laser printers typically support color, are more expensive, and are used (shared) by a
group of users. Shared laser printers typically print over 50 pages a minute.

3D Printers
3D printers, also known as additive manufacturing, create three-­dimensional
shapes by adding very thin layer after layer of material until the final shape is fully
formed. (See Figure 6-25.) There are a variety of different processes and materials
that can be used to create each layer. One of the most common sprays a liquid plas-

tic or plasticlike substance through a nozzle similar to an
inkjet printer.

3D printers are controlled by data describing the shape
of the object to be created. This data typically comes from
a file created by a 3D modeling program or from scan-
ning a physical model using a 3D scanner. Specialized
programs then take this data and further process it to
create data describing hundreds or thousands of horizon-
tal layers that when placed one on top of another form
the shape of the intended object. The printer uses this
data by extruding or cutting the first layer to very exact
specifications. Successive layers are then created and
attached to the layer below it until the product is final-
ized. The layers are so thin and so precise that they blend
together, making a final product that shows no sign of
the i­ndividual layers.

Commercial 3D printers have been used for decades.
Their cost, however, limited them to specialized manufacturing and research applica-
tions. Recently, however, their cost has dropped to as low as $200, making them avail-
able to individuals.

Other Printers
There are several other types of printers. These printers include cloud printers, ther-
mal printers, and plotters:
• Cloud printers are printers connected to the Internet that provide printing ser-

vices to others on the Internet. Google Cloud Print is a service that supports cloud
printing. Once a user activates a printer using the Google Chrome OS, the user
can access that printer anywhere with a smartphone or any other type of com-
puter that is connected to the Internet. For example, you could use a smartphone
from almost anywhere to send documents to be printed on a printer located at
your home or school.

154 chapter 6

• Thermal printers use heat elements to produce images on heat-sensitive privacy
paper. These printers are widely used with ATMs and gasoline pumps
to print receipts. Did you know that your printer
may be identifying itself in
• Plotters are special-purpose printers for producing a wide range of specialized every document that it creates?
output. Using output from graphics tablets and other graphical input devices, plot- Some color printers print nearly
ters create maps, images, and architectural and engineering drawings. Plotters are invisible dots in the margins of
typically used by graphic artists, engineers, and architects to print out designs, all printed documents. These
sketches, and drawings. microscopic dots form a code
that can be used to trace
concept check the printed page back to the
printer that generated it. Printer
Discuss these printer features: resolution, color capability, speed, memory, and manufacturers secretly developed
duplex printing. this code with the U.S. Secret
Compare inkjet, laser, and 3D printers. Service to assist in counterfeiting
Discuss cloud, thermal, and plotter printers. investigations. Some privacy
experts suggest that it is
inappropriate to track equipment
without the owner’s consent.

Audio-Output Devices

Audio-output devices translate audio information from the computer into sounds Figure 6-26  Headphones
that people can understand. The most widely used audio-output devices are s­ peakers
and headphones. (See Figure 6-26.) These devices connect to a sound card within
the system unit. This connection can be by cable to an audio jack on the system
unit, or the connection can be wireless. Wireless connections typically use Blue-
tooth technology. This type of connection requires special Bluetooth-enabled speak-
ers and/or headphones. Bluetooth will be discussed further in Chapter 8. The sound
card is used to capture as well as play back recorded sounds. Audio-output devices
are used to play music, vocalize translations from one language to another, and com-
municate information from the computer system to users.

Creating voice output is not anywhere near as difficult as recognizing and inter-
preting voice input. In fact, voice output is quite common. It is used with many smart-
phones, cars, and soft drink machines. It is used as a reinforcement tool for learning,
such as to help students study a foreign language. It also is used in many supermarkets
at the checkout counter to confirm purchases. One of its most powerful capabilities is
to assist the physically challenged.

Combination Input and Output Devices

Many devices combine input and output capabilities. Sometimes this is done to save
space. Other times it is done for very specialized applications. Common combination
devices include headsets, multifunctional devices, telephones, drones, robots, and vir-
tual reality headgear and gloves.

Headsets Figure 6-27  Headset
Headsets combine the functionality of microphones and headphones. The micro-
phone accepts audible input and headphones provide audio output. Headsets are an
integral part of serious video game systems. (See Figure 6-27.)

Input and Output 155

Figure 6-28  Drone Multifunctional Devices
Figure 6-29  Surgical robot Multifunctional devices (MFD) typically combine the capabilities of a scanner, printer,
fax, and copy machine. These multifunctional devices offer a cost and space advan-
tage. They cost about the same as a good printer or copy machine but require much
less space than the single-function devices they replace. Their disadvantages are lower
quality and unreliability. The output quality for any one function is often not quite as
good as that of the separate single-purpose devices. The reliability of multifunctional
devices suffers because problems with one of the functional parts can make the entire
device inoperable. Even so, multifunctional devices are widely used in home and small
business offices.
Telephones
Telephones are input and output devices for receiving and sending voice communica-
tion. Voice over IP (VoIP) is a set of standards or technologies that support voice and
other types of communication over the Internet. Telephony, also known as Internet
Telephony, is the VoIP application that uses Internet rather than traditional telephone
lines to support voice communication.

There are many VoIP services available for free that do not require any dedicated
hardware. Examples of these services are Skype from Microsoft, Hangouts from
Google, and FaceTime from Apple. Once you subscribe to a service, you can use your

smartphone or other type of computer to con-
nect to any other subscriber. These services are
free and support video as well as audio; however,
both parties must have their computers on and be
logged in to the service to send and receive calls.
For an additional fee, Skype allows you to call
non-Skype subscribers directly on their phone. To
learn more about Skype, see Making IT Work for
You: Skype, on pages 157–158.
Drones
Drones, or unmanned aerial vehicles (UAV), were
once too expensive for anything but military bud-
gets. However, today’s drones are inexpensive,
faster, and smarter, making them a valuable tool
and fun high-tech toy. (See Figure 6-28.) Most
drones take input from a controller from either a
radio joystick or a Wi-Fi connected tablet or lap-
top. The drones act as an output device, sending
back video and sound to the user. The resulting
combination of video and aerial maneuverability
has made drones a popular choice for a wide vari-
ety of activities ranging from amateur cinematog-
raphers to civil engineers.
Robots
Like drones, robotics has become relatively inex-
pensive with expanding capabilities. Robots use
cameras, microphones, and other sensors as
inputs. Based on these inputs, robotic outputs can
be as complex as exploring damaged nuclear reac-
tors to as simple as taking a photo. Robots can be
found almost everywhere including in a home vac-
uuming floors, in a factory assembling cars, on a
farm sorting produce, and in hospitals assisting in
surgery. (See Figure 6-29.)

156 chapter 6

Making IT work for you

SKYPE

Do you already use a communication tool that lets you keep in touch with your friends and family? Does that
tool include the ability to have face-to-face conversations, share files and screens, and make calls to those
not connected to the Internet? Skype is a well-known tool that offers all these services, most of them for
free. This section will help you explore some of Skype’s features. (Please note that the web is continually
changing, and some of the specifics presented below may have changed.)

Getting Started  In order to enjoy all the benefits of Skype,
it is recommended that your computer have speakers, a
microphone, and a webcam. If you have a laptop or tablet,
these are all likely integrated. Follow these steps to create
your account and install Skype on your machine:

• 1 Visit www.skype.com, and click the Download
Skype link.

• 2 Enter the required information to create your
Skype account. When you are finished, the
software will be downloaded automatically. Do
not purchase any Skype credits at the moment.

• 3 Run the downloaded setup file, and follow the
prompts to install Skype on your machine.

• 4 Log in to your Skype account on the welcome
screen, and follow the prompts to make sure
your audio and video are working.

Adding Contacts  You can find friends or other contacts manually, or you can import them from your address book on Face-
book, Outlook, and several other services. To add a contact manually:

• 1 Click next to the blue magnifying glass on the left
of the window under your log-in information.

• 2 Enter the name, Skype name, or e-mail address
you know about your contact, and hit Enter.

• 3 Skype will display matches. Click the one that
matches your contact’s details, and then click the
Add to Contacts button.
Your contact must accept your request before you can see
his or her online status.

157

Skype-to-Skype Communication  When two individuals have Skype accounts, they can contact each other (for free) using a
variety of methods, from voice or video calls to instant messages. They can exchange files and share screens with each other.
Please note that for videoconferencing between three or more people, you must have a premium or business account.

• 1 From the main screen, click on the contact you
wish to communicate with.

• 2 Click the blue video camera button to make a
video call or the blue handset button to make a
voice call. Once your contact accepts the call,
your interface will change.

• 3 During the call, you have the ability to send
instant messages and turn audio and/or video on
or off by clicking the buttons at the bottom.

• 4 To send files or share screens, click the Plus
(+) button at the bottom. You could also have
initiated the Send File feature from the contact
screen without having to place a call.

• 5 To hang up, press the red handset button at the bottom.

Calling Landline or Mobile Phones (VoIP)  Skype can use
your Internet connection to place a call to any phone in the
world. This is not a free service, but the costs are low. You
can pay as you go with Skype credits, or sign up for a monthly
subscription.

• 1 From the menu bar, select Call, and select Call
Phones.

• 2 Click the handset button after entering the phone
number.

158

Virtual Reality Headgear and Gloves
Virtual reality (VR) is an artificial, or simulated, reality
created in 3D by computers. It strives to create a virtual or
immersive experience by using specialized hardware that
includes headgear and gloves. (See Figure 6-30.)

The headgear has earphones and three-dimensional
stereoscopic screens. The gloves have sensors that collect
data about your hand movements. Coupled with software,
this interactive sensory equipment lets you immerse your-
self in a computer-generated world.

There are any number of applications for virtual real-
ity headgear and gloves. Automobile manufacturers use
virtual reality to evaluate what it would be like to sit in
the cars they have designed but not yet built. Virtual real-
ity is becoming a standard for high-end video games and Figure 6-30  Virtual reality headgear and gloves
for immersive movies. Sony and Facebook have heavily
invested in VR headsets as the future of computer interaction. Virtual reality promises
to become commonplace in the near future.

concept check

What are the two most widely used audio-output devices? What is Bluetooth?
What are headsets? Multifunctional devices? VoIP? Telephony?
What are drones? Robots? Virtual reality? Headgear? Gloves?

Ergonomics

People use computers to enrich their personal and private lives. There are ways, how-
ever, that computers can make people less productive and even harm their health.
Anyone who frequently uses a computer can be affected. As a result, there has been
great interest in a field known as ergonomics.

Ergonomics (pronounced “er-guh-nom-ix”) is defined as the study of human factors
related to things people use. It is concerned with fitting the task to the user rather
than forcing the user to contort to do the task. For computer users and manufacturers
this means designing input and output devices to increase ease of use and to avoid
health risks.

Sitting in front of a screen in awkward positions for long periods may lead to
physical problems such as eyestrain, headaches, and back pain. Computer users can
alleviate these problems by taking frequent rest breaks and by using well-designed
computer furniture. Some recommendations by ergonomics experts are illustrated in
Figure 6-31.

Other recommendations to avoid physical discomfort are
• Eyestrain and headache: To make the computer easier on the eyes, take a

15-m­ inute break every hour or two. Keep everything you’re focusing on at about
the same distance. For example, the computer screen, keyboard, and a document
holder containing your work might be positioned about 20 inches away. Clean the
screen of dust from time to time.
• Back and neck pain: To help avoid back and neck problems, make sure your
equipment is adjustable. You should be able to adjust your chair for height and
angle, and the chair should have good back support. The monitor should be at eye
level or slightly below eye level. Use a footrest, if necessary, to reduce leg fatigue.

Input and Output 159

Figure 6-31  Ergonomic recommendations
• Repetitive strain injury: Repetitive strain injury (RSI) is any injury that is caused

by fast, repetitive work that can generate neck, wrist, hand, and arm pain. RSI is
by far the greatest cause of workplace illnesses, resulting in compensation claims
totaling billions of dollars and lost productivity every year. One particular type
of RSI, carpal tunnel syndrome, found among heavy computer users, consists of
damage to nerves and tendons in the hands. Some victims report the pain is so
intense that they cannot open doors or shake hands and that they require cor-
rective surgery. Ergonomically correct keyboards have been developed to help
prevent injury from heavy computer use. (See Figure 6-32.) In addition to using
ergonomic keyboards, you should take frequent short rest breaks and gently mas-
sage your hands.

Figure 6-32  Ergonomic keyboard

160 chapter 6

Portable Computers
While the above recommendations apply to all personal computers, the design of por-
table computers including laptops, tablets, and smartphones presents some specific
ergonomic challenges.
• Laptops: Almost all laptops have attached keyboards and screens. Unfortunately,

it is impossible to optimally position either for safe ergonomic use. When the
screen is positioned appropriately at eye level, the keyboard is too high. When the
keyboard is appropriately positioned, the screen is too low. To minimize the nega-
tive impact, raise the level of the screen by using books or reams of paper under
the laptop and attach an external keyboard to be used at waist level.
• Tablets: Almost all tablets use a virtual keyboard and are designed to be held in your
hands, flat on a table, or slightly angled. These design features cause the user to
improperly align his or her head to the viewing surface, often causing neck and back
pain. This problem, sometimes referred to as tablet hunch, can be minimized by tak-
ing frequent breaks, moving around while working, using a tablet cover or stand that
allows the screen to be tipped at various angles, and using an external keyboard.
• Smartphones: Today, smartphones are more likely to be used for texting than talking.
As a result, thumbs are often used to type on a tiny keyboard. The result can be a pain
at the base or in the muscles of the thumb or wrist. This problem, sometimes referred
to as BlackBerry thumb, can be minimized by keeping wrists straight (not bent), head
up, and shoulders straight and frequently resting thumbs by using other fingers.
In today’s world, it is important to protect yourself by using computers appropriately.

concept check

What is ergonomics? How does it relate to input and output devices?
What can be done to minimize eyestrain, headache, back pain, and neck pain?
What is RSI? What is carpal tunnel syndrome?

Careers in IT Technical writers prepare instruction manuals, technical reports, and
other scientific or technical documents. Most technical writers work
Now that you’ve learned about input and out- for computer software firms, government agencies, or research institu-
tions. They translate technical information into easily understandable
“put devices, I’d like to tell you about my career instructions or summaries. As new technology continues to develop
”as a technical writer. and expand, the need for technical writers who can communicate tech-
nical expertise to others is expected to increase.

Technical writing positions typically require an associate’s or a bach-
elor’s degree in communications, journalism, or English and a special-
ization in, or familiarity with, a technical field. However, individuals
with strong writing skills sometimes transfer from jobs in the sciences
to positions in technical writing.

Technical writers can expect to earn an annual salary in the range of
$44,000 to $58,000. Advancement opportunities can be limited within
a firm or company, but there are additional opportunities in consulting.

Input and Output 161

A LOOK TO THE FUTURE

Augmented Reality Displays smartphone. You will be able to look at the sky and see infor-
mation about today’s weather. Text message and incoming
Have you ever run into someone who looks familiar, but you call notifications can appear in front of you. Prices from vari-
cannot remember her name or where you know her from? ous online stores will appear by the time you ask your friend
What about finding yourself in an unfamiliar town, constantly where he got that new T-shirt. And, of course, integrated
having to look at your smartphone or GPS to get directions? GPS will display arrows in front of you and guide you as you
Computers and the World Wide Web offer unrivaled infor- walk through unfamiliar city streets.
mation at the press of a button, but inputs have been limited
to desktops and keyboards. Smartphone cameras, GPS, and Although this technology will likely be available in the
screens now offer real-time, location-specific information to a next few years, there are some challenges. First, you have
user. In the future, with wearable augmented reality displays, the issue of powering the device. Some devices, such
information will appear instantly, right before your eyes. as a pair of glasses or contact lenses, may not be large
Data from your computer and the enough to include a battery capable of powering for all
Internet will become instantly acces-
sible and viewable without having to day. Another issue involves limita-
access another device. The reality tions of human vision. Normally,
you see in front of you is improved, our eyes find it difficult to focus
or augmented, with additional visual on objects that are placed very
information using projected images. close to them. Researchers have
Technology has been improving our come up with various solutions to
interactions with the real world, and fix this problem, but they need to
will continue to evolve to improve make it comfortable for the eyes to
our lives as we look to the future. shift focus between the information
being projected up close and the
Bringing up information about real-world object that could be far
a visual image is not new. Several away. Lastly, there is the issue of
search engines already have the comfort. Will these glasses or con-
ability to identify an image simply by tact lenses be comfortable to wear
looking for similar images in their all day? Will they make you look
databases. In addition, many types strange to those who do not know
of software can recognize faces about augmented reality?
by looking at key points in the facial structure in order to
identify the individual. These augmented reality displays will Many companies and universities
take that technology one step further by integrating it with are working on various types of augmented reality displays.
wearable glasses or contact lenses. Whether you look at a There are a few that have received funding from the military
landmark, textbook, or person, the computer connected to in order to assist soldiers and pilots. The ones that seem
that display will be able to retrieve the information you need closest to release for the general public are from Google.
and place it in your field of vision. So if you forgot the name Prototype eyeglasses from its “Project Glass” division are
of the person greeting you in the coffee shop, do not worry. already being tested by various Google employees. With the
Her name and brief biography will be retrieved from her release of Windows 10, Microsoft introduced HoloLens, an
social networking account and be displayed in front of you in augmented reality headset with embedded Windows soft-
time to properly return the greeting. ware that allows the user to interact with the digital and real
world through a pair of special glasses. Now that you have
Identification of people and objects is not the only use learned more about augmented reality, do you see yourself
of augmented reality. As technology continues to shrink in wearing these sorts of eyeglasses when they become afford-
size, the device will be able to perform all the tasks of your able? Do you think that they can end up being a dangerous
distraction?

162

VISUAL SUMMARY Input and Output

KEYBOARDS POINTING DEVICES

Input is any data or instructions that are used by a com- Pointing devices provide an intuitive interface with the
puter. Input devices translate words, numbers, sounds, system unit by accepting physical movements or gestures
images, and gestures that people understand into a form and converting them into machine-readable input.
that the system unit can process. These include keyboards
and pointing, scanning, image capturing, and audio-input Mouse
devices. A mouse controls a pointer that is displayed on the moni-
tor. The mouse pointer usually appears in the shape of
Keyboards convert numbers, letters, and special char- an arrow. Some mice have a wheel button that rotates to
acters that people understand into electrical signals. These scroll through information on the monitor. Optical mouse
signals are sent to, and processed by, the system unit. is the most widely used. A cordless or wireless mouse uses
radio waves or infrared light waves. A touch pad operates
Keyboards by touching or tapping a surface. It is widely used instead
There are four basic categories of keyboards: traditional, of a mouse with laptops and some types of mobile devices.
laptop, virtual, and thumb.
• Traditional keyboards, used on desktop and larger Touch Screens
Touch screens allow users to select actions by touching
computers. Standard keyboard has 101 keys. Toggle the screen with a finger or penlike device. Multitouch
keys turn features on and off. Combination keys screens accept multiple-finger commands.
perform actions when combinations of keys are held
down. Game Controllers
Game controllers provide input to computer games.
• Laptop keyboards, used on laptop computers. Smaller Widely used controllers include gaming mice, joysticks,
gamepads, and motion-sensing devices.
than traditional keyboard with fewer keys. Typically
does not have numeric keypad or standard location for Stylus
function and navigation keys. A stylus is typically used with tablets and mobile devices.
Often, a stylus interacts with handwriting recognition
• Virtual keyboard, primarily used on mobile devices software to translate handwritten notes into a form that
the system unit can process.
and tablets. Does not have a physical keyboard. Keys
displayed on screen and selected by pressing a key’s
image.

• Thumb keyboard, used on smartphones and other

small mobile devices. Designed primarily for commu-
nicating via texting and connecting to the web.

Input and Output 163

To efficiently and effectively use computers, you need to be aware of the most commonly used input and output devices.
These devices are translators for information into and out of the system unit. Input devices translate words, sounds,
and actions into symbols the system unit can process. Output devices translate symbols from the system unit into
words, images, and sounds that people can understand.

SCANNING DEVICES IMAGE CAPTURING DEVICES

Scanning devices move across text and images to convert Image capturing devices create or capture original images.
them into a form that the system unit can process. These devices include digital cameras and webcams.

Optical Scanners Digital Cameras
An optical scanner (scanner) converts documents into Digital cameras record images digitally and store them on
machine-readable form. The four basic types are flatbed, a memory card or in the camera’s memory. Most digital
document, portable, and 3D. cameras record video too.

Card Readers Webcams
Card readers interpret encoded information located on a Webcams are specialized digital video cameras that cap-
variety of cards. The most common is the magnetic card ture images and send them to a computer for broadcast
reader that reads information from a thin magnetic strip over the Internet. Webcams are built into many smart-
on the back of a card. Smart cards contain microchips to phones and tablets, while others are attached to the com-
encrypt data and improve security. puter monitor.

Bar Code Readers AUDIO-INPUT DEVICES
Bar code readers or scanners (either handheld wand read-
ers or platform scanners) read bar codes on products. Audio-input devices convert sounds into a form that can
There are a variety of different codes including the UPC be processed by the system unit. By far the most widely
and MaxiCode codes. used audio-input device is the microphone.

RFID Readers Voice Recognition Systems
RFID readers read RFID (radio-frequency identification) Voice recognition systems use a microphone, a sound
tags. These tags are widely used for tracking lost pets, pro- card, and special software. Siri, Cortana, and Google Now
duction, and inventory and for recording prices and prod- are digital assistants that use voice recognition. Special-
uct descriptions. ized portable voice recorders are widely used by doctors,
lawyers, and others to record dictation. Some systems are
Character and Mark Recognition Devices able to translate dictation from one language to another,
Character and mark recognition devices are scanners that such as from English to Japanese.
are able to recognize special characters and marks. Three
types are magnetic-ink character recognition (MICR),
optical-character recognition (OCR), and optical-mark
recognition (OMR).

164 chapter 6

MONITORS PRINTERS

Output is processed data or information. Output devices Printers translate information processed by the system
are hardwareised to provide or create output. Monitors unit and present the information on paper. Printer output
(d­ isplay screens) are the most-used output device. Output is often called hard copy.
is often referred to as soft copy.
Features
Features Basic features include resolution measured in dpi (dots
Monitor clarity is a function of resolution (matrix of ­pixels, per inch), color capability (most common black ink selec-
or picture elements), dot pitch, contrast ratio, size (active tion is grayscale), speed, memory, and duplex (both sides
display area), and aspect ratio. of paper) printing.

Flat-Panel Monitors Inkjet
Flat-panel monitors are the most widely used monitor. Inkjet printers spray ink at high speed onto the surface
Three basic types are LCD (liquid crystal display), LED of paper. They are the most widely used type of printer,
(light-emitting diode), and OLED (organic light-emitting reliable, quiet, and inexpensive. The most costly aspect of
diode). inkjet printers is replacing the ink cartridges.

Curved Monitors Laser
Curved monitors have concave screens, provide b­etter Laser printers use technology similar to photocopying
­viewing angles, and are widely used for high-end televisions. machine. There are two categories: personal and shared.

E-book Readers 3D Printer
E-books (electronic books) are traditional printed books 3D printers (additive manufacturing) create objects by
in electronic format. E-book readers (e-readers) store and adding layers of material onto one another. They have
display e-books and other electronic media. They use been available for decades; however, recent price reduc-
e-ink technology. tions have increased their popularity.

Other Monitors Other Printers
Other types of monitors include digital (interactive) There are several other types of printers, including cloud
whiteboards, ultra-high-definition television (UHDTV), printers (Google Cloud Print is a cloud printing service),
and digital projectors. thermal printers (use heat elements to produce images on
heat-sensitive paper), and plotters (use data from graphics
tablets and other graphical devices).

Input and Output 165

AUDIO-OUTPUT DEVICES ERGONOMICS

Ergonomics is the study of human factors related to things
people use.

Audio-output devices translate audio information from Recommendations
the computer into sounds that people can understand. The Some recommendations to avoid physical discomfort
most widely used are speakers and headphones. These associated with heavy computer use:
devices connect either by cable to an audio jack on the sys- • To avoid eyestrain and headache, take a 15-minute
tem unit or by a wireless connection. Bluetooth technology
is widely used to connect wireless devices. break every hour; keep everything you’re focusing on
at the same distance; and clean the screen periodically.
COMBINATION INPUT AND OUTPUT
DEVICES • To avoid back and neck pain, use adjustable equip-

Combination devices combine input and output capabili- ment; adjust chairs for height, angle, and back sup-
ties. Devices within this category include: port; position monitors at eye level or slightly below.
Use footrest, if necessary, to reduce leg fatigue.
• Multifunctional devices (MFD) typically combine
• To avoid repetitive strain injury (RSI) and carpal
capabilities of scanner, printer, fax, and copy machine.
­tunnel syndrome, use ergonomically correct key-
• Headsets combine the functionality of microphones boards; take frequent, short rest breaks; and gently
massage hands.
and headphones; integral part of serious video game
systems. Portable Computers
The design of portable computers presents ergonomic
• Telephones are input and output devices. Voice over challenges.
• Laptops do not allow correct positioning of keyboard
IP (VoIP) supports voice and other types of com-
munication over the Internet. Telephony (Internet and screen; raise level of laptop and use external
Telephony) is a VoIP application that uses Internet to keyboard.
support voice communication.
• Tablets with virtual keyboards cause improper align-
• Drones (unmanned aerial vehicles, UAV) take input
ment of user’s head; take frequent breaks, move while
from a controller and send output video and sound to working, use cover or stand, use external keyboard.
the user.
• Smartphones require extensive use of thumbs; keep
• Robots use cameras, microphones, and other sensors
wrists straight, head up, and shoulders straight and
as inputs; outputs can be as complex as exploring dam- use other fingers.
aged nuclear reactors to as simple as taking a photo.
CAREERS IN IT
• Virtual reality (VR) creates 3D simulated immersive
Technical writers prepare instruction manuals, technical
experiences. VR hardware includes headgear and reports, and other documents. An associate’s or a bache-
gloves. lor’s degree in communication, journalism, or English and
a specialization in, or familiarity with, a technical field are
required. Salary range is $44,000 to $58,000.

166 chapter 6

KEY TERMS

3D printer (154) headgear (159) platform scanner (146)
3D scanner (146) headphone (155) plotter (155)
active display area (149) headset (155) pointing device (144)
additive immersive experience (159) portable scanner (146)
inkjet printer (153) printer (153)
manufacturing (154) input (142) repetitive strain injury
aspect ratio (149) input device (142)
bar code (146) interactive (RSI) (160)
bar code reader (146) resolution (monitor) (149)
bar code scanner (146) whiteboard (151) resolution (printer) (153)
Bluetooth (155) Internet telephony (156) RFID reader (147)
card reader (146) joystick (144) RFID (radio-frequency
carpal tunnel keyboard (142)
laptop keyboard (143) identification) tag (147)
syndrome (160) laser printer (154) robots (156)
clarity (149) light-emitting diode scanner (146)
cloud printer (154) scanning device (146)
combination key (143) (LED) (150) shared laser printer (154)
contrast ratio (149) liquid crystal display smart card (146)
cordless mouse (144) soft copy (149)
curved monitor (150) (LCD) (150) speaker (155)
digital camera (148) magnetic card reader (146) stylus (145)
digital projector (151) magnetic-ink character technical writer (161)
digital whiteboard (151) telephone (156)
display screen (149) recognition (MICR) (147) telephony (156)
document scanner (146) MaxiCode (146) thermal printer (155)
dot pitch (149) monitor (149) thumb keyboard (143)
dots per inch (dpi) (153) motion-sensing toggle key (143)
drones (156) touch pad (144)
duplex printing (153) device (144) touch screen (144)
e-book reader (150) mouse (144) traditional keyboard (143)
e-books (150) mouse pointer (144) Universal Product Code
e-ink (150) multifunctional device
e-reader (150) (UPC) (146)
electronic book (150) (MFD) (156) ultra-high-definition
ergonomics (159) multitouch screen (144)
flat-panel monitor (150) optical-character recognition television
flatbed scanner (146) (UHDTV) (151)
game controller (144) (OCR) (147) virtual keyboard (143)
gamepads (144) organic light-emitting diode virtual reality (VR) (159)
gaming mice (144) unmanned aerial vehicle
gloves (159) (OLED) (150) (UAV) (156)
Google Cloud Print (154) optical-mark recognition voice over IP (VoIP) (156)
grayscale (153) voice recognition
handwriting recognition (OMR) (147) system (148)
optical mouse (144) wand reader (146)
software (145) optical scanner (146) webcam (148)
hard copy (153) output (149) wheel button (144)
output device (149) wireless mouse (144)
personal laser

printer (154)
picture element (149)
pixel (149)
pixel pitch (149)

chapter 6 167

MULTIPLE CHOICE

Circle the correct answer.

1. Most keyboards use an arrangement of keys known as:

a. Alpha c. OptiKey
b. Daisy d. QWERTY

2. The device that controls a pointer displayed on the monitor.

a. cord c. printer
b. mouse d. scanner

3. The type of screen that can be touched with more than one finger and supports zoom-
ing in and out by pinching and stretching your fingers.

a. digital c. multitouch
b. dynamic d. OLED

4. Flatbed and document are types of:

a. headsets c. monitors
b. MaxiCode d. scanners

5. Device used by banks to automatically read those unusual numbers on the bottom of
checks and deposit slips.

a. MICR c. OMR
b. FDIC d. UPC

6. The most widely used audio-input device.

a. mouse c. microphone
b. VR d. RFID

7. The monitor feature that indicates the ability to display colors.

a. aspect ratio c. dot pitch
b. contrast ratio d. resolution rate

8. Mobile devices able to store and display electronic media.

a. e-book readers c. lasers
b. HDTV d. whiteboards

9. Virtual reality strives to create this type of experience.

a. electronic c. LCD
b. immersive d. VoIP

10. The study of human factors related to things people use is:

a. ergonomics c. RSI
b. RFID d. telephony

168 chapter 6

MATCHING

Match each numbered item with the most closely related lettered item. Write your answers in
the spaces provided.

a. active display area 1. Pressing this key turns a feature on or off.
b. digital camera 2. Input device that controls a pointer that is
c. dot pitch
d. mouse displayed on the monitor.
e. plotters 3. A penlike device commonly used with tablet
f. scanners
g. Skype PCs and PDAs.
h. stylus 4. Bar code readers use either handheld wand
i. toggle key
j. UPC readers or platform _____.
5. Bar code system used by many electronic cash

registers.
6. Records images digitally on a memory card or

in its memory.
7. The distance between each pixel.
8. A monitor feature that is measured by the

diagonal length of the viewing area.
9. Special-purpose printers for creating maps,

images, and architectural and engineering
drawings.
10. A provider of lower-cost options for
telephony.

OPEN-ENDED

On a separate sheet of paper, respond to each question or statement.

1. Define input and input devices.
2. Describe the different types of keyboard, pointing, scanning, image capturing, and

audio-input devices.
3. Define output and output devices.
4. Describe the features and different types of monitors and printers.
5. Describe audio-output devices including Bluetooth technology.
6. Discuss combination input and output devices, including multifunctional devices, head-

sets, telephones, drones, robots, and virtual reality headgear and gloves.
7. Define ergonomics, describe ways to minimize physical discomfort, and discuss design

issues with portable computers.

chapter 6 169

DISCUSSION

Respond to each of the following questions.

1 Making IT Work for You: E-BOOKS

Are you tired of carrying a book bag filled with textbooks? Review the Making IT Work for You: E-books
on page 152, and then respond to the following: (a) Have you ever purchased or read an e-book? If so,
what was your most recent one? If not, have you considered it? Why or why not? (b) Download and install
an e-book app (desktop, tablet, or smartphone version), and then download a free e-book for that particu-
lar service. Identify the e-book you selected and describe your experience. (c) Based on your experience,
will you be purchasing more e-books in the future? Why or why not? (d) Would you consider buying
future textbooks as e-books? Discuss the advantages and disadvantages of e-book textbooks.

2 Making IT Work for You: SKYPE

Do you already use a communication tool that lets you keep in touch with your friends and family? Review
the Making IT Work for You: Skype on pages 157–158, and then respond to the following: (a) Have you ever
used Skype or a similar service? If so, what service have you used, and what do you typically use it for? If
you have not used Skype or a similar service, do you expect to in the future? Why or why not? (b) If you
do not have a Skype account, create a free one, and add one of your classmates as a contact. Try a few of
Skype’s features after connecting with your classmate, and then describe your experience with those fea-
tures. (c) Discuss the advantages and disadvantages of using Skype or a similar service for communication.

3 Privacy: PRINTERS AND ANONYMITY

Did you know that your printer may print personally identifying information on every document you print
without your knowledge or consent? Review the Privacy box on page 155, and respond to the following:
(a) It’s one thing that these codes can be used to identify a specific printer. But do you think the codes
can lead to identifying the person who owns the printer? Why or why not? (b) Do you think the hidden
codes are a violation of privacy? Explain your position. (c) Does a printer manufacturer have a duty to
assist the government in criminal investigations? Justify your position. (d) Does a printer manufacturer
have a duty to protect the privacy of its customers? Why or why not?

4 Ethics: WEBCAMS

Every day, thousands of webcams continuously broadcast images to the Internet. Review the Ethics box on
page 148, and respond to the following: (a) Do you think recording and broadcasting images without per-
mission is an ethical or a privacy concern? Why or why not? (b) Do you object to being recorded in public,
within a retail store, or in a private home? Explain. (c) Do you think police should have access to webcam
videos? Should concerned parents? Should jealous spouses? Why or why not? Defend your responses.

5 Environment: INKJET PRINTERS

Have you considered the environmental impact of using your inkjet printer? Review the Environment box
on page 153, and then respond to the following: (a) How often do you use your printer at home? What
sort of items do you typically print? (b) Have you considered any alternatives to printing? If so, what are
those alternatives? Why would or wouldn’t you use these alternatives? (c) Does the manufacturer of your
ink cartridges use recycled plastic? Support your answer with details from the manufacturer’s website.
(d) Find a store near you that accepts used ink cartridges. Name the store, and provide details on the
benefits it gives you for turning in cartridges.

170 chapter 6

PHOTO CREDITS

CHAPTER 6

Opener: © Colin Anderson/Blend Images LLC RF; p. 141, 162: © Blend Images/Colin Anderson/Getty Images RF;
p. 142, 161: © Chris Ryan/Getty Images RF; 6-1: © Willis Technology; 6-2 (top), p. 163 (left): © Nick Koudis/Getty
Images RF; 6-2 (middle) © CJG - Technology/Alamy; 6-2 (bottom): © tech gadgets/Alamy; 6-3: © Tetra Images/
Getty Images RF; 6-4: © cheekylorns/Getty Images RF; 6-5, p. 163 (right): © Ferran Traite Soler/ Getty Images/
RF; 6-6 (top-left): © Viacheslav Krisanov/Getty Images RF; 6-6 (top-right): Copyright © 2015 Razer Inc. All rights
reserved; 6-6 (bottom-right), 6-7: Used with permission from Microsoft; 6-6 (bottom-left): © alehdats/Getty Images
RF; 6-8, 6-13, p. 164 (right): Courtesy of Canon-Europe; 6-9: © 2015 MakerBot® Industries, LLC; 6-10, p. 164 (left):
© Lisa-Blue/Getty Images RF; 6-11: Paul J. Richards/AFP/Getty Images/Newscom; 6-12: © Junior Gonzales/Getty
Images RF; 6-14: © Medioimages/Photodisc/Getty Images RF; 6-15: © Maria Gritsai/Alamy RF; 6-17: © Stanca
Sanda/Alamy Stock Photo RF; 6-18: © adventtr/iStock/Getty Images RF; 6-19: © JB Reed/Bloomberg via Getty
Images; 6-20: Gerald Martineau/The Washington Post/Getty Images; 6-21, p. 165 (left): © scyther5/Getty Images
RF; 6-22, 6-24, p. 165 (right): © Copyright 2015 Epson America, Inc.; p. 152 (top): © Kristoffer Tripplaar/Alamy
Stock Photo; p. 152 (bottom): Photo by Simon Lees/PC Plus Magazine via Getty Images; 6-25: © scanrail/iStock/
Getty Images RF; 6-26, p. 166 (left): 2015 © Parrot SA. All rights reserved; 6-27: © Jesse Wild/PC Format Magazine
via Getty Images; 6-28: © Francois Nascimbeni/AFP/Getty Images; 6-29: © 2015 Intuitive Surgical, Inc. Used with
permission; p. 157 (all), 158 (both): Copyright © 2015 Skype and/or Microsoft; 6-30: © Chris Salvo/Getty Images;
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chapter 6 171

7chapter Secondary Storage

172

Why should I read this chapter?

If you don’t have the right secondary storage, your computer will
slow to a crawl, your digital camera won’t take pictures, and your
phone won’t be able to run apps. In the future, that will likely not
be a problem as we will see storage types that can hold the entire
U.S. Library of Congress on a single disk the size of a coin and
store information in holograms or even organic molecules.

This chapter covers the things you need to know to be prepared
for this ever-changing digital world, including:
• Hard drives—get the right hard drive on your computer to meet

all your needs.
• Optical discs—share digital information on Blu-ray, CD, or DVD.
• Solid-state storage—make your portable electronics faster and

use less power.
• Cloud storage—store your information safely and securely on

the Internet.

Learning Objectives

After you have read this chapter, you should be able to:
1 Distinguish between primary and secondary storage.
2 Identify the important characteristics of secondary storage including media, capacity, storage

devices, and access speed.
3 Describe hard-disk platters, tracks, sectors, cylinders, and head crashes.
4 Compare internal and external hard drives.
5 Compare performance enhancements including disk caching, RAID, file compression, and file

decompression.
6 Define optical storage including compact discs, digital versatile discs, and Blu-ray discs.
7 Define solid-state storage including solid-state drives, flash memory cards, and USB drives.
8 Define cloud storage and cloud storage services.
9 Describe mass storage, mass storage devices, enterprise storage systems, and storage area

networks.

173

Introduction Secondary storage devices are used to save, back up, and even transport
files consisting of data or programs from one location or computer to
“Hi, I’m James, and I’m a disaster recovery another. At one time, almost all files contained only numbers and letters.
specialist. I’d like to talk with you about sec- The demands for saving these files were easily met with low-capacity stor-
ondary storage, one of the most critical parts age devices.
of any computer system. I’d also like to talk
”about various cloud storage services. Data storage has expanded from text and numeric files to include digital
music files, photographic files, video files, and much more. These new types
of files require secondary storage devices that have much greater capacity.

Secondary storage devices have always been an indispensable element
in any computer system. They have similarities to output and input devices.
Like output devices, secondary storage devices receive information from
the system unit in the form of the machine language of 0s and 1s. Rather
than translating the information, however, secondary storage devices save
the information in machine language for later use. Like input devices, sec-
ondary storage devices send information to the system unit for processing.
However, the information, since it is already in machine form, does not
need to be translated. It is sent directly to memory (RAM), where it can be
accessed and processed by the CPU.

To efficiently and effectively use computers, you need to be aware of the
different types of secondary storage. You need to know the capabilities, limi-
tations, and uses of hard disks, solid-state drives, optical discs, cloud storage,
and other types of secondary storage. Additionally, you need to be aware of
specialty storage devices for portable computers and to be knowledgeable
about how large organizations manage their extensive data resources.

Storage

An essential feature of every computer is the ability to save, or store, information.
As discussed in Chapter 5, random-access memory (RAM) holds or stores data and
programs that the CPU is presently processing. Before data can be processed or a
program can be run, it must be in RAM. For this reason, RAM is sometimes referred
to as primary storage.

Unfortunately, most RAM provides only temporary or volatile storage. That is,
it loses all of its contents as soon as the computer is turned off. Its contents also
are lost if there is a power failure that disrupts the electric current going into the
system unit. This volatility results in a need for more permanent or nonvolatile
storage for data and programs. We also need external storage because users need
much more storage capacity than is typically available in a computer’s primary or
RAM memory.

Secondary storage provides permanent or nonvolatile storage. Using secondary
storage devices such as a hard-disk drive, data and programs can be retained after
the computer has been shut off. This is accomplished by writing files to and reading
files from secondary storage devices. Writing is the process of saving information

174 chapter 7

to the secondary storage device. Reading is the process of accessing
information from secondary storage. This chapter focuses on second-
ary storage devices.

These are important characteristics of secondary storage:

• Media are the physical material that holds the data and programs.
(See Figure 7-1.)

• Capacity measures how much a particular storage medium can
hold.

• Storage devices are hardware that reads data and programs from
storage media. Most also write to storage media.

• Access speed measures the amount of time required by the storage
device to retrieve data and programs.

Most desktop personal computer systems have hard-disk and optical disc
drives, as well as ports where additional storage devices can be connected.

Hard Disks

Hard disks save files by altering the magnetic charges of the disk’s Figure 7-1  Secondary storage
surface to represent 1s and 0s. Hard disks retrieve data and programs media
by reading these charges from the magnetic disk. Characters are rep-
resented by positive (+) and negative (-) charges using the ASCII, EBCDIC, or
Unicode binary codes. For example, the letter A would require a series of 8 charges.
(See Figure 7-2.) Density refers to how tightly these charges can be packed next to
one another on the disk.

Hard disks use rigid metallic platters that are stacked one on top of another. Hard
disks store and organize files using tracks, sectors, and cylinders. Tracks are rings of con-
centric circles on the platter. Each track is divided into invisible wedge-shaped sections
called sectors. (See Figure 7-3.) A cylinder runs through each track of a stack of platters.
Cylinders are necessary to differentiate files stored on the same track and sector of differ-
ent platters. When a hard disk is formatted, tracks, sectors, and cylinders are assigned.

Disk

Track
Sector

2122 2 2 2 1 Electromagnetic charges

0100 0 0 0 1 Binary representation

A Figure 7-3  Tracks and sectors

Figure 7-2  How charges on a disk surface
store the letter A

Secondary Storage 175